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Finding the Fourth Proportional to 388.62, 536.08 and 257.40

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Solution

The fourth proportional to 388.62, 536.08 and 257.40 is: 355.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    388.62 : 536.08 = 257.40 : x
  2. Step 2: Convert to fraction form
    388.62/536.08 = 257.40/x
  3. Step 3: Cross multiply
    388.62x = 536.08 × 257.40
  4. Step 4: Simplify right side
    388.62x = 137,986.99
  5. Step 5: Solve for x
    x = 137,986.99/388.62
  6. Step 6: Final answer
    x = 355.07

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.